<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<div>
    <!--v-model双向绑定-->
    <input type="text" v-model="info">
    {{info}}<br>
    用户名:<input type="text" placeholder="输入用户名" v-model="user.username"><br>
    密码:<input type="password" placeholder="输入密码" v-model="user.password">
</div>

<script src="https://cdn.staticfile.org/vue/2.2.2/vue.min.js"></script>
<script>
        let v = new Vue({
            el:"body>div",
            data:{
                info:"这是双向绑定",
                user:{
                    username:"",
                    password:""
                }
            }
        })
    </script>

</body>
</html>